This invention relates to a method and apparatus for producing vibrational energy and for using the resulting vibrational energy in a material transport system.
In the past there have been a variety of industrial applications for mechanical vibrators, such as in separators for screenable materials, grinding mills, and finishing mills for deburring metals, for example. A typical mechanical vibrator contemplated by this invention is the FM Series finishing mill manufactured by SWECO, Inc. of Los Angeles, California. Such a mechanical vibrator includes an annular vessel for containing parts to be finished and a suitable grinding media. A double-ended electric motor is fixed to the lower end of a cylindrical column, and calibrated counterweights are mounted at both ends of the motor shaft. The motor and the vessel are supported by compression springs, and the angular velocity developed by the motor output shaft vibrates the vessel and the material contained in it.
The present invention is based, in part, on the recognition that the drive motor of the mechanical vibrator described above is integrated into the active or vibrating portion of the system, which results in a large amount of vibration being transmitted to the motor and the motor bearings during use of the vibrator. Consequently, the motor bearings wear out in a relatively short length of time. The bearings are part of the motor and are difficult to remove for replacement, which adds substantially to the maintenance cost of the vibrator assembly. In addition, the recommendations of the motor supplier must be considered whenever it is desired to change the bearings.